A detent escapement answering the above description has already been proposed in Swiss Patent Application No. CH 641/75. Timepieces comprising detent escapements are highly prized for their precision. Detent escapements have, however, an important defect in that they are very sensitive to shocks. Consequently, they are reputed to be unsuitable for wristwatches. Indeed, when the watch is subjected to a shock in which the impulse pallet-stone receives an impulse from the escape wheel, the shock can cause a reverse rotation of the roller and unlock the escape wheel from the impulse pallet-stone which unlocks said wheel, which can then rotate freely and damage the drive train and the escapement.
It is an object of the present invention to overcome the drawbacks of the aforementioned prior art by providing a detent escapement with improved shock resistance allowing it, in particular, to be easily integrated into a wristwatch.